Magnetically Separable CuFe2O4 Nanoparticles Catalyzed Ligand-Free C-S Coupling in Water: Access to (E)- and (Z)-Styrenyl-, Heteroaryl and Sterically Hindered Aryl Sulfides

An efficient coupling of styrenyl, heteroaryl and sterically hindered aryl halides with aryl- and heteroarylthiols catalyzed by the bimetallic Cu and Fe nanomaterial, CuFe2O4, in water in the presence of tetrabutylammonium bromide and potassium phosphate (K3PO4) has been achieved without using any ligand. A series of unsymmetrical functionalized (E)- and (Z)-styrenyl aryl, heteroaryl heteroaryl and sterically hindered aryl aryl sulfides has been obtained by this procedure. The compounds are obtained in high yields and excellent stereoselectivity has been observed for styrenyl sulfides. The catalyst can be easily separated by an external magnet and recycled for ten times without any appreciable loss of activity. This procedure provides an easy access to useful and challenging biologically active organosulfides which are difficult to achieve by other methods.